1. Field of the Invention
The present invention relates to a scanning technique and, more specifically, to a technique for discontinuing scanning upon a determination that a reverse side of a document has been scanned in a scanner.
2. Description of the Related Art
In general, while one side of a document (hereinafter called a `front side`) includes an image for scanning, that is, black characters, tables, and graphics on white printing papers, the other side thereof (hereinafter called a `back or reverse side`) includes no image for scanning.
Namely, since a typical scanner scans one side of the document, a user performing the scanning operation uses the document whose front side has the image for scanning composed of black and white and the back side has a white image.
When the user inserts the document into the scanner, he must arrange the document and insert the document into scanner so as to scan the front side of the document. However, when the user is not accustomed to using the scanner or carelessly inserts the document wrong side up, the scanner scans the back side of the document.
Upon the user mistakenly inserting the document wrong side up into the scanner as described above, the scanner can not recognize the wrong insertion of the document, thereby unnecessarily scanning the back side of the document. Therefore, it results in power consumption, consumption of consumables, and so on. Further, in case of successively scanning a plurality of pages of the document, the problems, such as unnecessary power consumption and the consumption of consumables, increase more and more seriously.
Furthermore, the scanning of the back side of the document in a mechanism including the scanner, not a single scanner, causes another problem.
For instance, when the back side of the document in a copying mechanism including the scanner is scanned, the copying mechanism outputs the copied materials according to the back side of the document. Because the back side of the document in the copied materials according to the back side of the document is white, there is no image in the copied materials. As a result, it causes unnecessary power consumption and consumption of consumables due to the output of the copied materials which have no image from the copying mechanism.
Also, when the back side of the document in a facsimile system including the scanner is scanned, the facsimile system transmits the scanning data according to the back side of the document, to a place which the user determines beforehand. At this moment, since the back side of the document has no image for transmission, a receiving unit can not receive the image for transmission from a transmitting unit. In this case, it is troublesome for the transmitting unit to retransmit the document and thus, the user of the transmitting unit has to pay the communication costs for the unnecessary transmission.
As stated previously, when the document is inserted wrong side up into the scanner due to the mistake of the user, the scanner performs unnecessary scanning, thereby raising problems such as unnecessary power consumption and the consumption of consumables.
The patent to Yoshida, U.S. Pat. No. 4,839,740, entitled Image Processing Apparatus For Determining The Presence Or Absence Of An Image On Each Side Of A Plurality Of Originals Prior To Producing Two-Sided Copies Of The Originals To Avoid Producing Any Copies With Blank Sides, discloses an image processing apparatus which determines the presence or absence of an image on each of a plurality of originals prior to producing two sided copies of the originals to avoid producing any copies with blank sides.
The two patents to Amemniya, U.S. Pat. Nos. 5,488,485 and 5,392,135 entitled respectively Image Reading Apparatus, and Image Reading Apparatus Having Different Reading Speeds, and the patents to Nakajima and Morita et al., U.S. Pat. Nos. 5,481,354 and 5,347,351, entitled respectively Image Forming Apparatus, and Image Forming Apparatus For Copying One And Two-Sided Documents, each disclose image reading or image forming apparatus in which the front side of the document is distinguished from the back side thereof. Similarly, the patent to Telle, U.S. Pat. No. 5,298,937, entitled High Productivity Method And Apparatus For Scanning Simplex Or Duplex Originals, also discloses distinguishing the front side from the back side of a document. I have noticed that the foregoing reference seem to lack an efficacious arrangement in which scanning is stopped upon a determination that the back side of the document has been scanned.